C. E. Be Ranee — On the Surface- Geology of Cross Fell. 339 



from 1250 feet to about 1400 feet above the sea, tbe tbickness being 

 not less than 400 feet ; the pebbles are chiefly derived from the 

 Volcanic rocks of the Lake -district. 



From the fonns discovered by Dr. Nicholson in the beds of this 

 age, it would appear to have been deposited in very shallow water, 

 and at the base it often rests on old valleys, which in some cases 

 appear to coincide with the modem one in this direction, as Little 

 Dale, west of Grumply Fell, in the bottom of which occurs an 

 outlier of Old Eed Conglomerate, 100 feet below the base of the 

 main mass. This formation cuts off the upward extension of the 

 joints, fissures, and vertical dykes of siliceous red hsematite so 

 common in the Volcanic series under Cross Fell ; but whether the 

 iron in them, and in similar dykes in the Lake-district described 

 by the late Mr. John Bolton, was derived by percolation from the 

 red beds of the Old Eed Sandstone above, is a doubtful point, though 

 it is very possible that what may be called the primary or upper 

 valleys of the Lake-district were Old Eed lake-basins, from which 

 all Eed Beds have since been removed by later denudations, except 

 in the district flanking the Lake-district, as at Butterswick, and 

 near Ulleswater, etc., where Prof. Phillips, F.E.S., has described 

 them. 



Following Crowdundle beck to the watershed,^ the alluvial flats 

 disappear, the sides approach, and the valley becomes a V-shaped 

 gorge, with cliffs gradually steeper and steeper, various lime- 

 stones and sandstones dipping into the hill at about 15°, until 

 weathered basaltic columns of the Great Whin Sill are seen stand- 

 ing, each separate, like a row of gigantic figures against the sky- 

 line. This magnificent sheet of basalt, measured by the aneroid, 

 appeared to be 100 feet in thickness. Its upper surface, where cut 

 into a little notch by the beck, was about 1840 feet above the sea. 

 A little above occurs the Tyne-bottom Limestone, which reappears 

 on the dip, on the other side of the Fell, many miles to the east, 

 forming the bottom of the South Tyne. At about 2000 feet the 

 gorge rather widens, and a small waterfall occurs over a shale bed, 

 which is gradually being worn back under sandstone ; but it again 

 contracts, near a mine level, and becomes smaller and smaller, until 

 it is lost in a mere runnel, in the thick peat forming the col, 400 

 yards on the eastern side of which the Tees takes its source in a 

 similar runnel, at 2502 feet above the sea. 



From the col, which has an elevation of 2540 feet, down to the 

 Eiver Tyne, the country consists of long dreary moors sloping 

 gradually eastwards, through which the Tees has formed an ex- 



1 In addition to the great watershed running along the Cross Fell range in a 

 general N.N.W. direction, separating the waters that ilow into the North and Irish 

 Seas, another originates in the terraced scars of that mountain, running a little north 

 of east, separating the valleys of the Tees and the South Tjnie, passing near the 

 source of the latter river to Bel Beaver, on which is some evidence of an old camp, 

 from_ whence it turns northward to Burnhope Seat (2452), and runs along that range 

 of hills (the boundary between Durham and Cumberland, and afterwards, further 

 north, between the former and Nortluunberlund), parting the waters of Weardale 

 from, those of the rivers East and AVest Allen. 



